I bought these recently at a local antique shop, it was in a box among loads of other industrial dials an gages. And I stumbled upon these two. My thoughts are that at least the first one is from the RAF as it has the Air ministry symbol on it, and i suppose mit's from a pre WW2 aircraft as its dated 1938, the second I was told was from a First World War aircraft, but I doubt it But It does look quite old. This is not my area at all (if I ever had an area) so if anybody has any suggestions at all they would be greatly appreciated.
First Gage (with the white face) has the following things written on it
Howard Buttlers Ltd Walsall
I can make out B H W F
And the second (with the black face)
I can't see any markings